English Amiga Board


Go Back   English Amiga Board > Support > support.Hardware > Hardware mods

 
 
Thread Tools
Old 26 October 2020, 05:46   #1
IanP
Registered User

 
Join Date: Mar 2015
Location: Bristol/UK
Posts: 159
Raspberry Pi / Mushashi powered 68k Hardware Emulator

Claude Schwarz has posted on twitter that he has Diagrom running on an A500 with a Raspberry Pi and interface plugged into it where the 68000 should be.
https://twitter.com/Claude1079/statu...825558530?s=20

I don't know what sort of performance is possible with the CPU emulation on the Pi and the hardware interfacing. But there may be some interesting hybrid possibilities in addition to emulation (I'm thinking A314 on steroids).
IanP is offline  
Old 26 October 2020, 18:30   #2
Ernst Blofeld
<optimized out>

Ernst Blofeld's Avatar
 
Join Date: Sep 2020
Location: <optimized out>
Posts: 272
I'd love to know more about this, but I'm afraid I don't have the expertise to really understand it. The 7ish MHz that the 68K originally ran at is very slow by modern standards, but is it actually possible to interface something like a RaspberryPi to the 68K socket and actually make it work?
Ernst Blofeld is offline  
Old 26 October 2020, 19:07   #3
Niklas
Registered User

 
Join Date: Apr 2018
Location: Stockholm / Sweden
Posts: 81
Quote:
Originally Posted by Ernst Blofeld View Post
... but is it actually possible to interface something like a RaspberryPi to the 68K socket and actually make it work?
It is, he actually got it to run Pinball Dreams just today: https://twitter.com/Claude1079/statu...67372853190659
Niklas is offline  
Old 26 October 2020, 19:54   #4
Sim085
Registered User
 
Join Date: Apr 2009
Location: N/A
Posts: 773
Finally!

I have been dreaming about this since the first day the Raspberry Pi came out. Unfortunately I am no hardware guru (I am no hardware nothing actually) and therefore could never do anything about it. Finally projects like this are under development. Cannot wait for something similar also for the A1200.

Looking so forward for this.

Last edited by Sim085; 26 October 2020 at 20:00.
Sim085 is offline  
Old 26 October 2020, 20:06   #5
Sim085
Registered User
 
Join Date: Apr 2009
Location: N/A
Posts: 773
As I said I am no expert. However I believe for the Amiga changes nothing, signals are sent to the CPU and signals are returned from the CPU, the only difference is that the CPU is emulated by the raspberry pi. It is a great project. Wonder what pi resources can be shared.

Quote:
Originally Posted by Ernst Blofeld View Post
I'd love to know more about this, but I'm afraid I don't have the expertise to really understand it. The 7ish MHz that the 68K originally ran at is very slow by modern standards, but is it actually possible to interface something like a RaspberryPi to the 68K socket and actually make it work?

Last edited by Sim085; 27 October 2020 at 19:42.
Sim085 is offline  
Old 26 October 2020, 20:22   #6
IanP
Registered User

 
Join Date: Mar 2015
Location: Bristol/UK
Posts: 159
As I understand it he is using the GPIO connector in a mode called SMI (Secondary Memory Interface). This gives 18 data bits and 6 address bits and read/write signals. This talks to a MAX II CPLD on the interface card between the PI and the 68000 socket. The interface card also includes a set of latch ICs. So the PI can signal the CPLD probably using the SMI address lines and a combination of the read/write lines "the lower16 bits for the address latches are on the SMI databus", "the upper 8 bits for the address latches are on the SMI data bus", "8 or 16 bits to write to the databus latches are on the SMI databus" or "get the contents of the Amiga data bus into the latches", "put the contents of the data latches on the SMI databus". there are about 20 other signals (bus control, interupts etc.) on the 68000 that also need to be handled by the CPLD and PI.
IanP is offline  
Old 27 October 2020, 00:39   #7
Radertified
Registered User
 
Join Date: Jan 2011
Location: -
Posts: 483
According to the Musashi GitHub, it's a "68000, 68010, 68EC020, 68020, 68EC030, 68030, 68EC040 and 68040 emulator".

I've been waiting for FPGA as the next iteration of budget accelerators, but it may be Pi powered which is pretty exciting!
Radertified is offline  
Old 27 October 2020, 00:50   #8
jotd
This cat is no more
jotd's Avatar
 
Join Date: Dec 2004
Location: FRANCE
Age: 49
Posts: 5,089
Earlier this year, Musashi author allowed me to contribute to the emulator to fix 68040 features (missing/wrong instructions, FPU stuff), and I also suggested a few optimizations.

So if there are issues with Musashi itself I can help. Where Musashi is excellent is because of its architecture. It's rather quick to have something running with it.

(but of course Amiga custom chips aren't supported, but that probably doesn't matter here)
jotd is offline  
Old 27 October 2020, 01:55   #9
NovaCoder
Registered User
NovaCoder's Avatar
 
Join Date: Sep 2007
Location: Melbourne/Australia
Posts: 3,979
Yep this is very interesting, a cheap and fast accelerator would be great for the classics.

I've heard of a few of these hybrid cards being discussed over the years, I'd personally love to see an FPGA/ARM hybrid solution released as a plug in accelerator....that would be very cool.
NovaCoder is offline  
Old 27 October 2020, 11:21   #10
khph_re
Registered User
 
Join Date: Feb 2008
Location: Northampton/UK
Posts: 338
Quote:
Originally Posted by NovaCoder View Post
Yep this is very interesting, a cheap and fast accelerator would be great for the classics.

I've heard of a few of these hybrid cards being discussed over the years, I'd personally love to see an FPGA/ARM hybrid solution released as a plug in accelerator....that would be very cool.

Definitely, I've never watched any of the 060 demo's on real hardware, the gulf in cost between my 030 and an 060 has always been to great for me. I hope one of these devices can bridge that divide someday.

Last edited by khph_re; 27 October 2020 at 20:18.
khph_re is offline  
Old 27 October 2020, 18:45   #11
madgrizzle
Registered User

 
Join Date: Oct 2020
Location: Tallahassee
Posts: 2
It seems even with some hacked together support for fastmem, it is already pretty quick.

https://twitter.com/Claude1079/statu...22503716081665
madgrizzle is offline  
Old 27 October 2020, 20:02   #12
amiman99
Registered User

amiman99's Avatar
 
Join Date: Sep 2009
Location: San Antonio, TX USA
Age: 47
Posts: 1,074
This is what @majsta Vampire should have been, CPU and RAM, not plus everything else, or stand alone.
I hope something comes from it.
amiman99 is offline  
Old 27 October 2020, 21:32   #13
1NOM155
Registered User

1NOM155's Avatar
 
Join Date: Apr 2015
Location: Lisbon
Posts: 59
This could change a lot, its seems very promising project. congrats
1NOM155 is offline  
Old 28 October 2020, 00:22   #14
rare_j
Zone Friend

rare_j's Avatar
 
Join Date: Apr 2005
Location: London
Posts: 1,047
Quote:
Originally Posted by Sim085 View Post
Cannot wait for something similar also for the A1200.
Would probably be more difficult as there's no cpu socket for the 680ec20. It'd have to go on via the trapdoor connector I think which is more complicated.
rare_j is offline  
Old 28 October 2020, 00:57   #15
IanP
Registered User

 
Join Date: Mar 2015
Location: Bristol/UK
Posts: 159
Quote:
Originally Posted by amiman99 View Post
This is what @majsta Vampire should have been, CPU and RAM, not plus everything else, or stand alone.
I hope something comes from it.
The Raspberry PI could add everything the Vampire boards have and more if the software is written to make the features available from the emulator.
IanP is offline  
Old 28 October 2020, 04:46   #16
Bruce Abbott
Registered User

Bruce Abbott's Avatar
 
Join Date: Mar 2018
Location: Hastings, New Zealand
Posts: 492
Quote:
Originally Posted by amiman99 View Post
This is what @majsta Vampire should have been, CPU and RAM, not plus everything else, or stand alone.
I hope something comes from it.
"Everything else" being extra RAM, RTG and IDE? I disagree. What's the point of a fast CPU without those other things?

This Raspberry Pi CPU emulator is interesting, and could be attractive if it is cheap. However I doubt that it could match the performance of the Vampire, and I feel happier with real hardware anyway.

Seems a pity to use a Pi without the Amiga having access to its video, RAM, SD Card etc. Oops! I forgot, we don't want 'everything else'.
Bruce Abbott is offline  
Old 28 October 2020, 06:40   #17
amiman99
Registered User

amiman99's Avatar
 
Join Date: Sep 2009
Location: San Antonio, TX USA
Age: 47
Posts: 1,074
Quote:
Originally Posted by Bruce Abbott View Post
"Everything else" being extra RAM, RTG and IDE? I disagree. What's the point of a fast CPU without those other things?

This Raspberry Pi CPU emulator is interesting, and could be attractive if it is cheap. However I doubt that it could match the performance of the Vampire, and I feel happier with real hardware anyway.

Seems a pity to use a Pi without the Amiga having access to its video, RAM, SD Card etc. Oops! I forgot, we don't want 'everything else'.
When you add more features, you add more cost, adds dev time, you know feature creep. Then at the end it costs €300-€450.
I'm not saying Vampire is bad.
amiman99 is offline  
Old 28 October 2020, 09:15   #18
Sim085
Registered User
 
Join Date: Apr 2009
Location: N/A
Posts: 773
I always saw the advantage of putting a raspberry pi to emulate resources as a cheap alternative since the resources are there available to use on the raspberry pi and the raspberry pi is mass produced (unlike any amiga specific hardware).

I do not see why if the cpu and fast ram are emulated by the pi, why then storage cannot also be emulated by the pi. After all aren't those signals also going through the CPU socket? Maybe people with more knowledge then me can confirm or reject, I am really curious, I always thought so however given there are cards with ide.

I understand that the emulation software might not have reached that point (I do not know, maybe it already does). However the fun part is that this moves the problem to the software world rather then the hardware world + more powerful raspberry pi will continue to come out.

Quote:
Originally Posted by amiman99 View Post
When you add more features, you add more cost, adds dev time, you know feature creep. Then at the end it costs €300-€450.
I'm not saying Vampire is bad.

Last edited by Sim085; 28 October 2020 at 09:22.
Sim085 is offline  
Old 28 October 2020, 15:45   #19
madgrizzle
Registered User

 
Join Date: Oct 2020
Location: Tallahassee
Posts: 2
I agree scope creep drives price and delivery time up, but with him looking at moving to a CM4 with this, then the only Amiga-specific hardware is the carrier board. He could start with an initial version with just the functionality his adapter board currently has and down the road, if he desires, he could release a different version with hdmi, Ethernet, whatever. The CM4 would still remain the same. And if the CM5 comes out, people can just swap that in if he updates the software to support it. It provides a level of future-proofing that's not readily available with the current (and other future) accelerators out there. I have a 3640 with an '060 and am hesitant about some of the newer accelerator designs where you have to solder the '060 into them.
madgrizzle is offline  
Old 28 October 2020, 16:09   #20
roondar
Registered User

 
Join Date: Jul 2015
Location: The Netherlands
Posts: 2,647
That's quite cool!
Hope it ends up very successful, a PI based accelerator would be a very useful alternative for when the 680x0's start running out.
roondar is offline  
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Blitter emulator for 68k kamelito Coders. Asm / Hardware 20 01 November 2020 22:48
Raspberry PI SCSI emulator Jope Hardware mods 53 15 September 2019 22:42
Hatari ST emulator for 68K? Angus request.Apps 14 25 September 2013 21:31
amiga 68k emulator petee1979 support.OtherUAE 11 28 June 2008 11:07
68k Mega Drive Emulator Hewitson request.Apps 11 04 February 2008 09:55

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 01:50.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Page generated in 0.11688 seconds with 13 queries